81454464 has 384 divisors, whose sum is σ = 309304800. Its totient is φ = 20901888.

The previous prime is 81454447. The next prime is 81454469. The reversal of 81454464 is 46445418.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81454469) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2201454 + ... + 2201490.

Almost surely, 2^81454464 is an apocalyptic number.

81454464 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81454464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154652400).

81454464 is an abundant number, since it is smaller than the sum of its proper divisors (227850336).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81454464 is a wasteful number, since it uses less digits than its factorization.

81454464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87 (or 62 counting only the distinct ones).

The product of its digits is 61440, while the sum is 36.

The square root of 81454464 is about 9025.2126844745. The cubic root of 81454464 is about 433.4825605704.

It can be divided in two parts, 81454 and 464, that added together give a palindrome (81918).

The spelling of 81454464 in words is "eighty-one million, four hundred fifty-four thousand, four hundred sixty-four".